Whether fans viewed Taylor Swift as a victim or a fiend, the West-Swift phone call only confirmed their prejudices

When Kim Kardashian-West released a video on Snapchat on Monday, it seemed designed to end Taylor Swift.

The video records part of a phone call between Swift and Kardashians husband, Kanye West. Swift has alleged that his song Famous includes misogyny directed at her in a lyric where West calls her that bitch. West, however, claims he received her approval before releasing the song. The video seems to validate Wests story in the clip, he voices a few lyrics, while Swift seems to sweetly utter approval.

But instead of inciting a mass critique of Swift, the video seems to have polarized opinions on the pop star even further.

The Swift-ians have been quick to point out the foibles with the Kardashian-West video: the editing is choppy. Taping it might be illegal. And, absent from the video is the true smoking gun: Kayne using the word bitch to describe Swift.

The West-ians, however, have doubled down on their interpretation: the video itself is evidence that Taylor lies, since she denied any lyric-specific exchange occurring between the two.

The evidence given to both groups (one blurry video) is the same, but what facts they lift from it, and how they choose to interpret those facts, are wildly different. Why does such a simple artifact a phone conversation between two megawatt celebrities inspire such seemingly contradictory reactions?

The answer may be, in part, a simple phenomenon called confirmation bias.

Confirmation bias refers to our tendency to seek out, recall and interpret information that validates our own beliefs. When we look for evidence, we unconsciously sort for the bits that back up our own opinion. When we interpret information, our understanding is skewed to whatever we initially believed to be true.

Partially, this is helpful. To make sense of the vast array of details, ideas and information in the world, our brains rely on some organizing principles to sort out what is important and what can be discarded. We have to form connections somehow, and basing them on what we already believe to be true helps to fortify our own reasoning. But its also why it can be so frustrating to debate someone with an opposing viewpoint. It can feel like theyre inhabiting an alternate universe. And, in a way, they are.

This divided court of public opinion isnt just limited to celebrity gossip. Earlier this month, when Diamond Reynolds streamed video of her boyfriend, Philando Castile, bleeding after being shot by a police officer in a traffic stop, people scrutinized her vocal tone and word choice. In the video, Reynolds describes what is happening and responds to the officers questions with a polite, yes, sir.

On Twitter, Reynolds was lambasted for her strange, detached bedside manner, which naysayers used as evidence that the shooting was staged, that Reynolds was a sociopath who was unconcerned that her boyfriend was dying in front of her eyes. Later, when psychologists described her seemingly calm tone as a common reaction to extreme shock, it was seen as self-preservatory and an act of political defiance.

Cognitive bias is also a helpful explanation for why the United States seems to fracture into two groups every time Donald Trump gives a speech. Trumps stump speech is full of broad aphorisms and platitudes, the kind of things that make it easy to interpret as you wish.

For white, working-class men, Trumps motto Make America Great Again could be interpreted as a rallying cry about economic policy and job creation. For others, Trumps racist rhetoric (easily dismissed by his followers) means that the slogan may as well be written, Make America White Again. As Trump surged in the polls this spring, a large swath of Americans found his meteoric rise inconceivable and terrifying evidence that America is batty and racist. But its also about which of Trumps foibles people find prescient, and which they choose to discard.

Its even harder to think objectively when youre looking at a person, like Trump or Swift, who is famous. Speaking on this years presidential election, Timothy Calkins, a professor of marketing at the Kellogg School of Management at Northwestern University, told the Huffington Post that its even more difficult to shift someones opinion once they believe they know something.

When you force people to really think about something, it is difficult and challenging, <a href=”http://www.huffingtonpost.com/entry/hillary-clinton-donald-trump-election_us_572cae72e4b016f378957726″ data-link-name=”in” body link” class=”u-underline”>said Calkins. And the easy thing to do is to just not think about it. For someone to really challenge and change their beliefs requires a lot of energy.

Few of us are personally acquainted with Trump, West, Swift or Kardashian-West, but their fame is ubiquitous enough that most of us have an opinion about them, one thats easily stoked by the tiny indeterminate pieces of information we can sort through and assemble to bolster our own sense of moral superiority.